What is a camera “watermark”?
Answer
In repair terminology, a camera “watermark” is not text added by photo software. It usually means a dark spot, grey dot or blurred mark that repeatedly appears in the same place in photos or video, often more visible against a light background.
iPhone camera modules contain magnetic and moving parts. Internal components move during operation, and dust that enters the module and adheres to the sensor (CMOS) or another optical component can produce a fixed mark in the image.
Surface dirt on the lens, dust inside the module, moisture and sensor damage can create similar symptoms. Cleaning and physical inspection are needed to identify the cause and whether it can be repaired.